Monero: Fails to compile against musl libc

[wang-gretzky]

Running Void Linux, with musl libc. Build fails due to musl's lack of execinfo.h.

In file included from /tmp/monero-0.10.3.1/contrib/epee/include/misc_log_ex.h:61:0,
                 from /tmp/monero-0.10.3.1/contrib/epee/include/serialization/keyvalue_serialization.h:31,
                 from /tmp/monero-0.10.3.1/src/p2p/p2p_protocol_defs.h:34,
                 from /tmp/monero-0.10.3.1/src/common/util.h:43,
                 from /tmp/monero-0.10.3.1/src/common/base58.cpp:39:
/tmp/monero-0.10.3.1/external/easylogging++/easylogging++.h:345:25: fatal error: execinfo.h: No such file or directory
 #   include <execinfo.h>
                         ^
compilation terminated.
make[3]: *** [src/common/CMakeFiles/obj_common.dir/build.make:63: src/common/CMakeFiles/obj_common.dir/base58.cpp.o] Error 1
make[2]: *** [CMakeFiles/Makefile2:486: src/common/CMakeFiles/obj_common.dir/all] Error 2
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [Makefile:141: all] Error 2
make: *** [Makefile:59: release-all] Error 2

[danrmiller]

This is the same case for OpenBSD.

https://build.getmonero.org/builders/monero-static-openbsd-amd64/builds/4/steps/compile/logs/stdio

There are several platforms without execinfo. I think @moneromooo-monero said its used by easylogging to get stack trace info and so maybe we should just include it on glibc linux.

[moneromooo-monero]

Can you try replacing it with elf.h and see if that builds ?

[danrmiller]

@moneromooo-monero OpenBSD doesn't have an elf.h but it does have sys/exec_elf.h, which looks about the same. If I use that instead of execinfo.h I get "use of undeclared identifier" errors for val, backtrace, and backtrace_symbols.

@wang-gretzky What about on Void Linux?

[moneromooo-monero]

Do you see these symbols anywhere ? If not, then I guess this can be disabled for that platform.

[danrmiller]

Do you see these symbols anywhere ?

No.

[moneromooo-monero]

Does this work ? https://github.com/monero-project/monero/pull/2235

[misery]

I added a package to AlpineLinux. Alpine uses musl: https://git.alpinelinux.org/cgit/aports/tree/testing/monero
There are some glitches to enable musl support. See the patches.

[moneromooo-monero]

Interesting, I thought __has_include was a CLANG only thing. Looks like it's in GCC 5 now.
Also, ideally, the CMakeLists.txt patch should be unnecessary if the easylogging one is applied. What are the errors if it is omitted ?

[misery]

Just to avoid a lot of warnings

In file included from /home/andre/aports/testing/monero/src/monero-0.10.3.1/contrib/epee/include/misc_log_ex.h:61:0,
                 from /home/andre/aports/testing/monero/src/monero-0.10.3.1/contrib/epee/include/serialization/keyvalue_serialization.h:31,
                 from /home/andre/aports/testing/monero/src/monero-0.10.3.1/src/cryptonote_basic/cryptonote_basic.h:46,
                 from /home/andre/aports/testing/monero/src/monero-0.10.3.1/src/blockchain_utilities/bootstrap_file.h:37,
                 from /home/andre/aports/testing/monero/src/monero-0.10.3.1/src/blockchain_utilities/blockchain_export.cpp:29:
/home/andre/aports/testing/monero/src/monero-0.10.3.1/external/easylogging++/easylogging++.h:205:11: warning: #warning "Stack trace not available for this compiler"; [-Wcpp]
 #         warning "Stack trace not available for this compiler";
           ^~~~~~~

_has_include will be in C++17

[moneromooo-monero]

Ah, that makes sense, thanks.

[moneromooo-monero]

I've updated the patch to remove the warning except once.

[danrmiller]

This is what I get with #2235. I wonder if we might revive it since #2249 has been abandoned. I can give you access to an openbsd box.

```[ 43%] Building CXX object external/easylogging++/CMakeFiles/easylogging.dir/easylogging++.cc.o
In file included from /home/vagrant/monero/external/easylogging++/easylogging++.cc:18:
/home/vagrant/monero/external/easylogging++/easylogging++.h:216:13: warning: "Stack trace not available for this compiler"; [-W#warnings]

warning "Stack trace not available for this compiler";

        ^

/home/vagrant/monero/external/easylogging++/easylogging++.cc:718:1: warning: control may reach end of non-void function [-Wreturn-type]
}
^
/home/vagrant/monero/external/easylogging++/easylogging++.cc:1038:8: error: use of undeclared identifier 'val'
if ((val == nullptr) || ((strcmp(val, "") == 0))) {
^
/home/vagrant/monero/external/easylogging++/easylogging++.cc:1038:36: error: use of undeclared identifier 'val'
if ((val == nullptr) || ((strcmp(val, "") == 0))) {
^
/home/vagrant/monero/external/easylogging++/easylogging++.cc:1052:22: error: use of undeclared identifier 'val'
return std::string(val);
^
2 warnings and 3 errors generated.
```

[moneromooo-monero]

Sure, I'll fix if I have access to one.

[moneromooo-monero]

I think it's fixed with ston1th's latest commits.

[ston1th]

@moneromooo-monero unfortunately my commits just fixed the OpenBSD part, not the musl libc.

I just fired an Alpine Linux VM to test some solutions (maybe a generic one) using __has_include and/or __GNU_LIBRARY__.

[danrmiller]

@ston1th We have a builder for alpine, looks like its close, needs a -lz maybe?
https://build.getmonero.org/builders/monero-static-alpine-3.5-x86_64/builds/1146/steps/compile/logs/stdio

[ston1th]

@danrmiller
Huh I'm bit confused now.
I tried to build master on Alpine 3.6 and got the <execinfo.h> error. I try a clean VM later on.

Anyway.. yes I think there needs to be a -lz.
But I'm not sure this will fix these two errors:

[ 91%] Linking CXX executable ../../bin/monero-wallet-rpc
../../external/easylogging++/libeasylogging.a(easylogging++.cc.o): In function `el::base::debug::StackTrace::generateNew()':
easylogging++.cc:(.text+0xc7da): undefined reference to `backtrace'
easylogging++.cc:(.text+0xc7e6): undefined reference to `backtrace_symbols'

@moneromooo-monero I looked through https://github.com/monero-project/monero/pull/2235 and I would like to add those two (#2235-R17, #2235-R212) so we don't spam the build logs with warnings if execinfo is not available.

[moneromooo-monero]

2900 is merged.

[TimeTravelersHackedMe]

apk add libexecinfo-dev

[moneromooo-monero]

Is this still happening ?

[andypost]

meanwhile it happened again http://build.alpinelinux.org/buildlogs/build-edge-armhf/testing/monero/monero-0.13.0.2-r0.log

[  5%] No download step for 'generate_translations_header'
-- The most recent tag was at c93942e1ed
-- You are ahead of or behind a tagged release
In file included from /home/buildozer/aports/testing/monero/src/monero-0.13.0.2/external/easylogging++/easylogging++.cc:18:
/home/buildozer/aports/testing/monero/src/monero-0.13.0.2/external/easylogging++/easylogging++.h:216:10: warning: #warning "Stack trace not available for this compiler"; [-Wcpp]
 #        warning "Stack trace not available for this compiler";
          ^~~~~~~

[andypost]

apk add libexecinfo-dev

this also does not help and without patch it fails on linking

[ 80%] Linking CXX executable ../../bin/monero-blockchain-export
/usr/lib/gcc/x86_64-alpine-linux-musl/8.2.0/../../../../x86_64-alpine-linux-musl/bin/ld: ../../external/easylogging++/libeasylogging.a(easylogging++.cc.o): in function `el::base::debug::StackTrace::generateNew()':
easylogging++.cc:(.text+0xd51d): undefined reference to `backtrace'
/usr/lib/gcc/x86_64-alpine-linux-musl/8.2.0/../../../../x86_64-alpine-linux-musl/bin/ld: easylogging++.cc:(.text+0xd529): undefined reference to `backtrace_symbols'
collect2: error: ld returned 1 exit status

Ref https://travis-ci.org/alpinelinux/aports/builds/445387732

[cornfeedhobo]

I can confirm this, but I think the issue might be upstream. Currently using a patch as a workaround.

Edit: If libunwind is present, a completely different set of errors is reported, so the suggestion in the linked issue seems fruitless.

[cornfeedhobo]

We're back to this failing for 0.15.x.x. I haven't figured out a patch yet.

[cornfeedhobo]

This disables the ~stack traces~ crash logs. Best compromise I can come up with right now.

export CXXFLAGS="${CXXFLAGS} -DELPP_FEATURE_CRASH_LOG"

[moneromooo-monero]

This enables crash logs. Did you mean -U ?

[jbg]

It builds successfully on Alpine with -DELPP_FEATURE_CRASH_LOG, so I guess it does disable crash logs @moneromooo-monero

[codebling]

For posterity (because this issue comes up first in a number of search results for musl-related linking errors, especially related to easylogging), the switch that did it for me was -DSTACK_TRACE:BOOL=OFF (every other patch or switch suggested in this thread either did not work or gives a 404).

Sorry for the necrobump